Another source of hardware statistics!

[Dan Kegel]

Unity3d is a game engine for casual gaming (not hardcore gaming).
They have some good data on their user base's hardware at

http://unity3d.com/webplayer/hwstats

e.g. their breakdown of video cards for this quarter is at
http://unity3d.com/webplayer/hwstats/pages/web-2008Q4-gfxcard.html

Their top 3 graphics cards are
Intel 945 (GMA 950)	13.3%	
Nvidia GeForce 6100	7.5%	
ATI Radeon X300/X550/Xpress200/1100	6.9%

And believe it or not, 8% of their users still only have 256MB of RAM...
- Dan